SIST-TS CEN ISO/TS 21596:2022

SLOVENSKI STANDARD
SIST-TS CEN ISO/TS 21596:2022
01-januar-2022
Trdna biogoriva - Določanje stopnje mletja - Metoda trdega grozda za toplotno
obdelana goriva iz biomase (ISO/TS 21596:2021)
Solid biofuels - Determination of grindability - Hardgrove type method for thermally
treated biomass fuels (ISO/TS 21596:2021)
Biogene Festbrennstoffe - Bestimmung der Mahlbarkeit - Hardgrove-Verfahren für
thermisch behandelte Brennstoffe aus Biomasse (ISO/PRF TS 21596:2021)
Biocombustibles solides - Détermination de la broyabilité - Méthode de type Hardgrove
pour les combustibles de biomasses traitées thermiquement (ISO/TS 21596:2021)
Ta slovenski standard je istoveten z: CEN ISO/TS 21596:2021
ICS:
75.160.40 Biogoriva Biofuels
SIST-TS CEN ISO/TS 21596:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TS CEN ISO/TS 21596:2022

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SIST-TS CEN ISO/TS 21596:2022


CEN ISO/TS 21596
TECHNICAL SPECIFICATION

SPÉCIFICATION TECHNIQUE

November 2021
TECHNISCHE SPEZIFIKATION
ICS 75.160.40
English Version

Solid biofuels - Determination of grindability - Hardgrove
type method for thermally treated biomass fuels (ISO/TS
21596:2021)
Biocombustibles solides - Détermination de la Biogene Festbrennstoffe - Bestimmung der
broyabilité - Méthode de type Hardgrove pour les Mahlbarkeit - Hardgrove-Verfahren für thermisch
combustibles de biomasses traitées thermiquement behandelte Brennstoffe aus Biomasse (ISO/TS
(ISO/TS 21596:2021) 21596:2021)
This Technical Specification (CEN/TS) was approved by CEN on 28 September 2021 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to
submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS
available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in
parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN ISO/TS 21596:2021 E
worldwide for CEN national Members.

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SIST-TS CEN ISO/TS 21596:2022
CEN ISO/TS 21596:2021 (E)
Contents Page
European foreword . 3

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SIST-TS CEN ISO/TS 21596:2022
CEN ISO/TS 21596:2021 (E)
European foreword
This document (CEN ISO/TS 21596:2021) has been prepared by Technical Committee ISO/TC 238
"Solid biofuels" in collaboration with Technical Committee CEN/TC 335 “Solid biofuels” the secretariat
of which is held by SIS.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO/TS 21596:2021 has been approved by CEN as CEN ISO/TS 21596:2021 without any
modification.


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SIST-TS CEN ISO/TS 21596:2022

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SIST-TS CEN ISO/TS 21596:2022
TECHNICAL ISO/TS
SPECIFICATION 21596
First edition
2021-10
Solid biofuels — Determination of
grindability — Hardgrove type method
for thermally treated biomass fuels
Biocombustibles solides — Détermination de la broyabilité —
Méthode de type Hardgrove pour les combustibles de biomasses
traitées thermiquement
Reference number
ISO/TS 21596:2021(E)
© ISO 2021

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SIST-TS CEN ISO/TS 21596:2022
ISO/TS 21596:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
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CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
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  © ISO 2021 – All rights reserved

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SIST-TS CEN ISO/TS 21596:2022
ISO/TS 21596:2021(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
5.1 Standard HGI mill . 2
5.2 Sieves . 2
5.3 Glass measuring cylinder . 2
5.4 Sieving machine . 3
5.5 Balance . 3
5.6 Cutting mill . 3
6 Sampling and sample preparation . 3
6.1 General . 3
6.2 Moisture conditions . 3
6.3 Pre-grinding and sieving . 3
6.4 Sample size . 3
7 Procedure .3
8 Calculation . 4
9 Reproducibility . 5
10 Test report . 5
Annex A (normative) Calibration curve and thermally treated biomass grindability index
(TTBGI) values for the reference materials. 6
Bibliography . 9
iii
© ISO 2021 – All rights reserved

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SIST-TS CEN ISO/TS 21596:2022
ISO/TS 21596:2021(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 238, Solid biofuels, in collaboration with
the European Committee for Standardization (CEN) Technical Committee CEN/TC 335, Solid biofuels, in
accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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  © ISO 2021 – All rights reserved

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SIST-TS CEN ISO/TS 21596:2022
ISO/TS 21596:2021(E)
Introduction
Grindability characteristics are of fundamental importance during solid biofuel preparation for energy
conversion processes, requiring a predictable particle size distribution. Particles that are too large or
too wide in their distribution may result in feeding problems as well as un-burnt fuel passing through
the conversion process. Also, in case of processing of biomass for pre-treatment, consistency in particle
size determines the yield of such pre-treatment as well as the quality of the final solid biofuel.
The effectiveness of combustion in a pulverized fuel furnace depends strongly on the reactivity and
particle size distribution of the pulverized fuel among other factors. For coal, the Hardgrove Grindability
Index (HGI) test was developed to characterize the relative grindability of a particular quality of coal
relative to a pre-determined standard quality of coal (ASTM D409). The HGI test is an empirical batch
method that simulates the continuous grinding and crushing operation of a ball, table or tube type of
industrial coal pulverizer, herein also called coal mill. The HGI value is an indication of the degree of
grinding required to reach a particular particle size necessary for effective combustion.
Manufacturers of coal pulverizers for preparation of pulverized coal for combustion in coal burning
plants provide curves that show the relationships between the HGI for coal, coal mill capacity in terms
of tonne/h and coal mill power in kW. This is done as part of the boiler contract and guarantees. It
also serves as a first indication as to how to operate a mill when pulverizing different coals with
predetermined standard properties. A HGI of 50, which is standard industry convention, implies that
100 % capacity in tonnes per hour (as indicated) can be reached for the coal at a fineness of 70 % less
than 75 microns and 99,5 % less than 300 microns. If a coal has a HGI of less than 50 it implies some
level of pulverizer capacity loss while on the other hand, a HGI higher than 50 indicates some level
of pulverizer capacity gain. The HGI method is internationally accepted and quoted as part of the
specification of coal for international trade.
Grindability may also be applied to thermally pre-treated compressed biomass materials, such as
pellets, for pulverization in coal mills. Pre-treatment methods for biomass fuels such as torrefaction,
steam treatment or hydro-thermal carbonization (HTC) upgrade the properties of biomass making it
more effective as a fuel. With increasing interest in the use of such pre-treated biomass fuels for direct
co-firing applications in conventional pulverized coal boilers, this method herein describes a laboratory
procedure for determination of the grindability of pre-treated biofuels for powder fuel preparation.
The HGI determination is subject to many limitations, including the fact that measurements can be
insensitive to the heterogeneous properties of coal that arise from different mineral contents, maceral
constituents and levels of maturity. Three relevant adaptations are applied to the standard HGI method
in order to extend its applicability to thermally pre-treated biomass fuels. The adaptations and their
justification are as follows:
— Amount of sample used for the test determination.
— Particle size used as basis for defining grindability.
— Reference materials for establishing the calibration curve.
0.1 Amount of the sample used for test determination
Coal pulverizers are volumetric devices but with the densities of coals being fairly similar, the capacity
of these devices is expressed in mass units per hour. In contrast different biomass materials have
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different densities. Therefore, the sample amount was changed to the volume (75 ± 0,5) cm of input
material, which approximates the bulk volume of the standard reference coal samples with a particle
size between 1,18 mm and 600 μm.
0.2 Particle size used as basis for defining grindability
The standard HGI test for coal uses the mass of particles passing a sieve with an aperture size of 75 μm
as criteria for determining the grindability and the resulting HGI value. The furnace volume is designed
from the knowledge of coals to be utilized so as to provide an adequate residence time for c
...